The present invention relates to a carbon black, and particularly, the present invention relates to a carbon black having remarkably improved blackness. Such carbon black is suitably used as pigments in paints, inks, resins, etc.
Among the commercially produced pigments, carbon black has the smallest particle size. Since it possesses high hiding power and tinting strength, it has been used as black pigments in paints, inks, resins, etc. The blackness is mainly attributed to its particle size and the improvement of the blackness is attained by decreasing the particle size and increasing the specific surface area. However, the decrease of the particle size causes the problem of worsening dispersibility, and as a result, adjustment of the amount of a surface volatile component (surface oxygen-containing functional group) has been proposed.
The carbon black is mainly classified according to methods of manufacture, into channel black and furnace black. The furnace black is usually insufficient in blackness compared with the channel black. Especially, to use as a high-quality carbon black for color which is required to have a small particle size and a high specific surface area, it is necessary to conduct an after-treatment for in improving the dispersibility.
The conventional carbon black with improved blackness as mentioned above does not always gave good dispersibility. A carbon black with high blackness which shows an excellent dispersibility and is usable in a wide range of commercial applications has been still demanded.
The present inventors have found that when a carbon black with specific physical properties is provided, its blackness can be remarkably improved without decreasing the particle size, namely, without worsening the dispersibility. The present invention has been attained based on the finding.